The US has detained more than 80,000 people in facilities from Afghanistan to Cuba since the attacks on the World Trade Centre four years ago, the Pentagon said yesterday. The disclosure comes at a time of growing unease about Washington's treatment of prisoners in its "war on terror" and Europe's unknowing help in the CIA's practice of rendition.

The Bush administration has defended the detentions from criticism by human rights organisations, saying the interrogation of suspected militants has been crucial in its attempt to dismantle terror networks. At least 14,500 people are in US custody in connection with the war on terror, Pentagon officials in Washington and Baghdad said yesterday. Some 13,814 people are being held in Iraq and there are approximately 500 at Guantánamo Bay in Cuba.

But it was an even less visible aspect of America's detention policy that was causing a furore in European capitals yesterday: the CIA practice of rendering terror suspects for interrogation to secret prisons in third countries. Washington faced mounting pressure yesterday to respond to reports of secret landings by private jets used by the CIA to transport terror suspects in at least six countries. "If these allegations turn out to be true, the crucial thing is whether these flights landed in the member states with or without the knowledge and approval of the authorities," Terry Davis, the Council of Europe's secretary general, said.

The CIA has repeatedly declined to comment on reports it has transported terror suspects through European countries. The practice has been widely condemned by human rights organisations for operating outside the scrutiny of the courts and for transporting prisoners to countries known to use torture. Spain, Portugal, Norway, Sweden, Denmark and Iceland are all reported to have served as stopovers for such flights.

The revelations have deepened disquiet about European collaboration with the more disturbing aspects of America's war on terror. This month it was reported that the CIA had situated two of its secret prisons in Romania and Poland.

The council, which has named a Swiss senator, Dick Marty, to investigate the allegations, called for cooperation with the inquiry yesterday. "This issue goes to the very heart of the Council of Europe's human rights mandate," René van der Linden, the president of the parliamentary assembly, said in a speech to the Council of Europe's executive body.

Meanwhile in Baghdad, Iraq's interior minister, Bayan Jabr, suggested yesterday that those alleging torture of prisoners were seeking to settle political scores. He also denied that most of the 170 detainees found by US troops this week locked in an interior ministry bunker in Baghdad were Sunni Muslims.